Thanks everyone for your replies. Unfortunately I don't have a photo of the fruit. The last few years it did develop a fungus (which I think is called plum pocket). You can see a withered plum in the second picture. Before that though, the fruit was always good and sweet. theaceofspades: you may be right about it being planted from a pit. That sounds like something that my grandfather, whose property it was, would have done. destin_gardener: It didn't have any thorns. From my online reading, I think that yes, it is likely a Canada or American plum. It was really a hearty tree for being so far north, so I think a native tree is probably a good guess. Thanks again. And if anyone has an idea, please chime in!

The common name is "Norfolk Island Pine" that could be a source of confusion. They are most commonly found in the US in supermarkets during the holidays as for most, it's an indoor Christmas tree. In warm climates like Florida they can be grown outdoors and can get quite huge. And by huge I mean picture a 200' pipe cleaner.

My guess would be Persian Walnut (Juglans regia). Also very good quality - you might want to think about selling it to a sawmiller for furniture, etc (if the sawmiller can be offered any guarantee the tree has never had any nails hammered into it!) Resin

You guys are not particularly helpful. Or nice. My best guess, and this is only a guess, would be that it's a maple tree. In the second picture, to the right of your ear, there's a scale of bark separating from the top side that looks thin (which can make climbing hard). When a scale of maple bark separates it can be relatively thin like that, whereas other common trees, oak or walnut, usually have thicker, bark that doesn't scale as much. On the flip side, it doesn't look as scaly as I would expect from say cherry. Without more info I'd guess maple.